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arXiv · 1702.08253

Distributed fiber sparse-wideband vibration sensing by sub-Nyquist additive random sampling

Jingdong Zhang·Hua Zheng·Tao Zhu·Guolu Yin·Min Liu·Yongzhong Bai·Dingrong Qu·Feng Qiu·Xianbing Huang
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Abstract

The round trip time of the light pulse limits the maximum detectable vibration frequency response range of phase-sensitive optical time domain reflectometry (ϕ-OTDR). Unlike the uniform laser pulse interval in conventional ϕ-OTDR, we randomly modulate the pulse interval, so that an equivalent sub-Nyquist additive random sampling (sNARS) is realized for every sensing point of the long interrogation fiber. For an ϕ-OTDR system with 10 km sensing length, the sNARS method is optimized by theoretical analysis and Monte Carlo simulation, and the experimental results verify that a wide-band spars signal can be identified and reconstructed. Such a method can broaden the vibration frequency response range of ϕ-OTDR, which is of great significance in sparse-wideband-frequency vibration signal detection, such as rail track monitoring and metal defect detection.

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Jingdong Zhang, Hua Zheng, Tao Zhu, Guolu Yin, Min Liu, Yongzhong Bai, Dingrong Qu, Feng Qiu, Xianbing Huang. 2018-03-21. Distributed fiber sparse-wideband vibration sensing by sub-Nyquist additive random sampling. https://doi.org/10.1364/ol.43.002022

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